Elastic fabric



Jan. 9, 1940. KENDRlCK 2,186,531

ELASTIC FABRIC Filed April 25, 1938 2 Sheets-Sheet 1 INVENTOR:

A V4 I TiOR/VEY Jan. 9, 1940. B KENDRICK 2,186,531

ELASTIC FABRIC Filed April 23, 1938 2 Sheets-Sheet 2 a L 595E Li I!!!1311- II! n I II INVENTOP.

U4 2 't/Larf]. endr wl,

Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE mns'nc memoApplication April 23, 1988, Serial No. 203,754

2 Claim.

This invention relates to improvements in elastic fabrics of the kindemployed in the manufacture of wearing apparel and surgical appliances.Such fabrics comprise a body or ground 5 work of knit or woven fabricand laterally adiacent elastic strands enclosed by the threads of thebody or ground work in a manner to permit the fabrics in theirentireties to be stretched in directions longitudinally of the strands.

Each elastic strand of such fabrics comprises a freely stretchable,elastic, rubber thread forming the core of the strand and a suitablecovering which surrounds the core. The rubber core of the strandis heldin an elongated or stretched condition by the covering which surroundsthe same; and, while the covering holds the core stretched from itsnormal condition and permits further stretching thereof, the stretchedcondition in which it is normally held by the covering is When pieces offabrics of the character above described are sewed together or sewed topieces of fabrics of other kinds, it frequently happens that the needleused in the sewing operation pierces some of the rubber cores of thestrands, sometimes leaving the sewing thread extending through the coresand sometimes merely leaving holes or broken edge portions in the cores;and the frequent stretching and release of the elastic fabric of thearticle of wearing apparel or the surgical appliance containing therubber cores thus impaired causes them to break. After the cores havethus been broken the tendency thereof to resume their normal lengths hascaused them to recede from the points of breakage not only through thebody or ground work of the fabrics containing them but also through thecoverings surrounding the cores, during the continued stretching andrelease of the fabric; and this continued stretching and release of thefabric has caused the end portions of the cores resulting from thebreaking thereof to protrude from within the main body of the fabric ina manner to impair the emciency of the article or appliance and torender it rough and unsightly.

The object of the invention is to overcome or lessen or entirelyeliminate the aforesaid objection by providing the fabric with anelastic strand having a rubber core and a covering therefor of suchnovel construction that the recession or shifting of the entire strandwithin the body of the fabric from the region of the point of breakre ofthe rubber core thereof and also the recession or shifting of the corewithin its surrounding s covering from the region of such point, will befor from the limit to which it may be stretched.

reduced to a great extent or entirely eliminated, with the result thatthe number and size of the protruding end portions of the broken rubbercores will be reduced or entirely eliminated from the fabric.

With the foregoing and related objects in view the invention resides inthe elements and the combinations of them hereinafter .described andclaimed.

In the accompanying drawings, illustrating the invention,

Figure l is a side view, greatly enlarged, of a length of an elasticstrand of the fabric embodying the invention, showing certain partsofthe covering threads unwrapped from the core of the strand and brokenaway to expose portions of the core.

Figure 2 is a transverse section of the strand, on line 2-2 of Fig. 1.

Figure 3 is a view of a length of the tape of the covering of the rubbercore, enlarged.

Figure 4 is a view similar to Fig. 3, showing a modification of theinterweaving of the threads forming the tape.

Figure 5 is a view of the complete fabric.

v Referring to Figs. 1 to 4 of the drawings, 3 designates the core ofthe strand, the same being constructed of freely stretchable, elastic,rubber.

Thecore 3 is enclosed within and surrounded by a covering consisting offibrous threads 4 and a tape 5 formed of a plurality of interwovenfibrous threads. The threads of the tape 5 may be interwoven in the formof braid, as shown in Fig. 3, which I have found to give very goodresults, or they may be interwoven as longitudinally extending warpthreads and transversely extending weft threads. as shown in Fig. 4.

Any suitable number of the threads 4 may be employed. As hereinillustrated, two threads 4 are used and they are wrapped spirally aroundthe core and advance longitudinally thereof.-

The tape 5 is wrapped spirally around the core I reversely of thethreads .4, in closely arranged helices which advance longitudinally ofthe core I.

In producing my improved elastic strand, the core 3 thereof is stretchedlongitudinally-to a length which is several times its normal length,and, while it is held in this stretched condition,

the threads 4 and the tape I are applied thereto.

in the order named. When the core 3 is released from this stretchedcondition, after the application of the threads 4 and tape 5 thereto,the core contracts longitudinally and expands transversely and returnsto a length which may be several times its normal length. and, in thiscondition,

the further return toward its normal length is prevented by the threads4 and tape 5.

The extent to which the rubber core 3 is stretched when the threads 4and tape 5 are applied thereto, and the extent to which the rubber corereturns toward its normal length thereafter may vary greatly within thescope of the invention such variation being governed by the charactdr ofthe rubber of the core with reference to the resistance which it offersto being stretched.

The tape 5 lies flat upon the core 3 and the threads 4 surrounding it,and the tape advances in regularly formed, closely related helices, andit completely encloses the core 3 and threads 4 and presents arelatively smooth and even exterior surface for the strand as a whole,both when the strand is in a normal or unstretched condition and afterit has been stretched.

When the core 3 is released after the application of the tape 5 thereto,the longitudinal contraction of the core crowds the helices of the tapetogether, and crowds the several interwoven threads of the tapetogether, and, when the complete strand is stretched from its normalcondition, the crowded condition of the helices and the interwoventhreads of the tape are relieved by movements thereof which tend toseparate them. Such forward and back movements of the helices andthreads, during the elongation and contraction of the strand, preservethe strands relatively smooth and even exterior surface in allconditions thereof when it is in service.

Referring now to Fig. 5 of the drawings, the complete elastic fabricillustrated therein comprises elastic strands 6 arranged side by sideand having the characteristics hereinbefore described, and co-operatingbinding threads 1. The elastic strands 6 are bound within the fabric andheld in place therein, in side by side relationship, by the bindingthreads 'Iwhich are knitted together and form a network which extendsthroughout the fabric and encloses the strands in pockets formed by andbetween the loops of adjacent binding threads.

I'have discovered that the employment of the tape 5 in the covering forthe rubber core 3 provides an elastic strand which, when used in myimproved elastic fabric, will virtually eliminate the objectionalresults which have heretofore been present when the rubber core of thestrand has been pierced or broken or otherwise damaged by a sewingneedle, as hereinbefore pointed out, because the needle which damagesthe core pierces the body of the covering tape 5 on opposite sides ofthe core and leaves a stitch which extends through the tape and securesthe tape to the body of the fabric. This stitch extends through theloops of the binding threads of the fabric and between interwoventhreads of the tape of the elastic strand, and the interweaving of thethreads prevents the raveling thereof and causes the interwoven threadsof the tape, at the crossings of such threads, to form effectivebarriers which engage the thread of the stitch and effectively preventeither the tape or the rubber core which it encloses or both fromshifting their positions within the fabric longitudinally of the strandor from pulling away from the region of the damaged strand core.

I claim:

1. An elastic fabric comprising elastic strands arranged side by side,and. co-operating binding threads retaining the elastic strands inpockets formed by and between adjacent binding threads, each elasticstrand comprising a stretchable, elastic, rubber core and a coveringsurrounding the core, said covering comprising a tape wrapped spirallyaround the core and being formed of a plurality of interwoven fibrousthreads, said core being stretched beyond the normal length thereof andbeing held in such stretched condition by said covering, whereby when asewing thread stitch extends through the binding threads of the fabricand through the tape of a strand having a rubber core which is damagedin the region of the stitch, the stitch will prevent the core and itscoveriing from being pulled from the region of the stitch longitudinallyof the strand.

2. An elastic fabric comprising elastic strands arranged side by side,and co-operating binding whereby when a sewing thread stitch extendsthrough the binding threads of the fabric and through the tape of astrand having a rubber core which is damaged in the region of thestitch,.the stitch will prevent the core and itscovering from beingpulled from the region of the stitch longitudinally of the strand.

ARTHUR B. KENDRICK.

